diff --git a/src/cmd/asm/internal/asm/endtoend_test.go b/src/cmd/asm/internal/asm/endtoend_test.go
index 8986281f10..bc992a7c99 100644
--- a/src/cmd/asm/internal/asm/endtoend_test.go
+++ b/src/cmd/asm/internal/asm/endtoend_test.go
@@ -5,6 +5,7 @@
 package asm
 
 import (
+	"bufio"
 	"bytes"
 	"fmt"
 	"io/ioutil"
@@ -17,7 +18,6 @@ import (
 	"testing"
 
 	"cmd/asm/internal/lex"
-	"cmd/internal/bio"
 	"cmd/internal/obj"
 )
 
@@ -34,7 +34,7 @@ func testEndToEnd(t *testing.T, goarch, file string) {
 	pList := obj.Linknewplist(ctxt)
 	var ok bool
 	testOut = new(bytes.Buffer) // The assembler writes test output to this buffer.
-	ctxt.Bso = bio.BufWriter(os.Stdout)
+	ctxt.Bso = bufio.NewWriter(os.Stdout)
 	defer ctxt.Bso.Flush()
 	failed := false
 	ctxt.DiagFunc = func(format string, args ...interface{}) {
@@ -272,7 +272,7 @@ func testErrors(t *testing.T, goarch, file string) {
 	pList := obj.Linknewplist(ctxt)
 	var ok bool
 	testOut = new(bytes.Buffer) // The assembler writes test output to this buffer.
-	ctxt.Bso = bio.BufWriter(os.Stdout)
+	ctxt.Bso = bufio.NewWriter(os.Stdout)
 	defer ctxt.Bso.Flush()
 	failed := false
 	var errBuf bytes.Buffer
diff --git a/src/cmd/asm/main.go b/src/cmd/asm/main.go
index 75cb8f75d3..f010ca93f1 100644
--- a/src/cmd/asm/main.go
+++ b/src/cmd/asm/main.go
@@ -5,6 +5,7 @@
 package main
 
 import (
+	"bufio"
 	"flag"
 	"fmt"
 	"log"
@@ -32,11 +33,6 @@ func main() {
 
 	flags.Parse()
 
-	// Create object file, write header.
-	fd, err := os.Create(*flags.OutputFile)
-	if err != nil {
-		log.Fatal(err)
-	}
 	ctxt := obj.Linknew(architecture.LinkArch)
 	if *flags.PrintOut {
 		ctxt.Debugasm = 1
@@ -46,9 +42,14 @@ func main() {
 	if *flags.Shared || *flags.Dynlink {
 		ctxt.Flag_shared = 1
 	}
-	ctxt.Bso = bio.BufWriter(os.Stdout)
+	ctxt.Bso = bufio.NewWriter(os.Stdout)
 	defer ctxt.Bso.Flush()
-	output := bio.BufWriter(fd)
+
+	// Create object file, write header.
+	output, err := bio.Create(*flags.OutputFile)
+	if err != nil {
+		log.Fatal(err)
+	}
 	fmt.Fprintf(output, "go object %s %s %s\n", obj.Getgoos(), obj.Getgoarch(), obj.Getgoversion())
 	fmt.Fprintf(output, "!\n")
 
diff --git a/src/cmd/compile/internal/gc/bexport.go b/src/cmd/compile/internal/gc/bexport.go
index bb0a34e67b..15e5e3ada6 100644
--- a/src/cmd/compile/internal/gc/bexport.go
+++ b/src/cmd/compile/internal/gc/bexport.go
@@ -90,9 +90,9 @@ importer.
 package gc
 
 import (
+	"bufio"
 	"bytes"
 	"cmd/compile/internal/big"
-	"cmd/internal/bio"
 	"encoding/binary"
 	"fmt"
 	"sort"
@@ -124,7 +124,7 @@ const exportVersion = "v0"
 const exportInlined = true // default: true
 
 type exporter struct {
-	out      *bio.Writer
+	out      *bufio.Writer
 	pkgIndex map[*Pkg]int
 	typIndex map[*Type]int
 	inlined  []*Func
@@ -136,7 +136,7 @@ type exporter struct {
 }
 
 // export writes the exportlist for localpkg to out and returns the number of bytes written.
-func export(out *bio.Writer, trace bool) int {
+func export(out *bufio.Writer, trace bool) int {
 	p := exporter{
 		out:      out,
 		pkgIndex: make(map[*Pkg]int),
diff --git a/src/cmd/compile/internal/gc/export.go b/src/cmd/compile/internal/gc/export.go
index 2f94b9c62f..dc7c0869bf 100644
--- a/src/cmd/compile/internal/gc/export.go
+++ b/src/cmd/compile/internal/gc/export.go
@@ -384,7 +384,7 @@ func dumpexport() {
 		if debugFormat {
 			// save a copy of the export data
 			var copy bytes.Buffer
-			bcopy := bio.BufWriter(&copy)
+			bcopy := bufio.NewWriter(&copy)
 			size = export(bcopy, Debug_export != 0)
 			bcopy.Flush() // flushing to bytes.Buffer cannot fail
 			if n, err := bout.Write(copy.Bytes()); n != size || err != nil {
@@ -407,7 +407,7 @@ func dumpexport() {
 			pkgs = savedPkgs
 			pkgMap = savedPkgMap
 		} else {
-			size = export(bout, Debug_export != 0)
+			size = export(bout.Writer(), Debug_export != 0)
 		}
 		exportf("\n$$\n")
 	} else {
diff --git a/src/cmd/compile/internal/gc/go.go b/src/cmd/compile/internal/gc/go.go
index ec7e219d95..d9b28ff8e6 100644
--- a/src/cmd/compile/internal/gc/go.go
+++ b/src/cmd/compile/internal/gc/go.go
@@ -5,6 +5,7 @@
 package gc
 
 import (
+	"bufio"
 	"cmd/compile/internal/ssa"
 	"cmd/internal/bio"
 	"cmd/internal/obj"
@@ -288,7 +289,7 @@ var Ctxt *obj.Link
 
 var writearchive int
 
-var bstdout *bio.Writer
+var bstdout *bufio.Writer
 
 var Nacl bool
 
diff --git a/src/cmd/compile/internal/gc/main.go b/src/cmd/compile/internal/gc/main.go
index 03143f5d0a..26acf8861f 100644
--- a/src/cmd/compile/internal/gc/main.go
+++ b/src/cmd/compile/internal/gc/main.go
@@ -9,7 +9,6 @@ package gc
 import (
 	"bufio"
 	"cmd/compile/internal/ssa"
-	"cmd/internal/bio"
 	"cmd/internal/obj"
 	"cmd/internal/sys"
 	"flag"
@@ -104,7 +103,7 @@ func Main() {
 
 	Ctxt = obj.Linknew(Thearch.LinkArch)
 	Ctxt.DiagFunc = Yyerror
-	bstdout = bio.BufWriter(os.Stdout)
+	bstdout = bufio.NewWriter(os.Stdout)
 	Ctxt.Bso = bstdout
 
 	localpkg = mkpkg("")
diff --git a/src/cmd/internal/bio/buf.go b/src/cmd/internal/bio/buf.go
index 0bd4658cdd..983ce46627 100644
--- a/src/cmd/internal/bio/buf.go
+++ b/src/cmd/internal/bio/buf.go
@@ -51,18 +51,6 @@ func Open(name string) (*Reader, error) {
 	return &Reader{f: f, r: bufio.NewReader(f)}, nil
 }
 
-// BufWriter returns a Writer on top of w.
-// TODO(dfc) remove this method and replace caller with bufio.Writer.
-func BufWriter(w io.Writer) *Writer {
-	return &Writer{w: bufio.NewWriter(w)}
-}
-
-// BufWriter returns a Reader on top of r.
-// TODO(dfc) remove this method and replace caller with bufio.Reader.
-func BufReader(r io.Reader) *Reader {
-	return &Reader{r: bufio.NewReader(r)}
-}
-
 func (w *Writer) Write(p []byte) (int, error) {
 	return w.w.Write(p)
 }
diff --git a/src/cmd/internal/obj/link.go b/src/cmd/internal/obj/link.go
index c48c3d807f..62175f9ed8 100644
--- a/src/cmd/internal/obj/link.go
+++ b/src/cmd/internal/obj/link.go
@@ -31,7 +31,7 @@
 package obj
 
 import (
-	"cmd/internal/bio"
+	"bufio"
 	"cmd/internal/sys"
 )
 
@@ -629,7 +629,7 @@ type Link struct {
 	Flag_shared   int32
 	Flag_dynlink  bool
 	Flag_optimize bool
-	Bso           *bio.Writer
+	Bso           *bufio.Writer
 	Pathname      string
 	Goroot        string
 	Goroot_final  string
diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
index e35306dd0e..01dca9fc31 100644
--- a/src/cmd/link/internal/ld/lib.go
+++ b/src/cmd/link/internal/ld/lib.go
@@ -241,7 +241,7 @@ const (
 var (
 	headstring string
 	// buffered output
-	Bso *bio.Writer
+	Bso *bufio.Writer
 )
 
 // TODO(dfc) outBuf duplicates bio.Writer
diff --git a/src/cmd/link/internal/ld/link.go b/src/cmd/link/internal/ld/link.go
index cbcc979c85..52b52f1cc0 100644
--- a/src/cmd/link/internal/ld/link.go
+++ b/src/cmd/link/internal/ld/link.go
@@ -31,7 +31,7 @@
 package ld
 
 import (
-	"cmd/internal/bio"
+	"bufio"
 	"cmd/internal/sys"
 	"debug/elf"
 	"fmt"
@@ -165,10 +165,9 @@ type Link struct {
 	Headtype  int
 	Arch      *sys.Arch
 	Debugvlog int32
-
-	Bso     *bio.Writer
-	Windows int32
-	Goroot  string
+	Bso       *bufio.Writer
+	Windows   int32
+	Goroot    string
 
 	// Symbol lookup based on name and indexed by version.
 	Hash []map[string]*LSym
diff --git a/src/cmd/link/internal/ld/pobj.go b/src/cmd/link/internal/ld/pobj.go
index 50066d32d7..f4fb4d4845 100644
--- a/src/cmd/link/internal/ld/pobj.go
+++ b/src/cmd/link/internal/ld/pobj.go
@@ -31,7 +31,7 @@
 package ld
 
 import (
-	"cmd/internal/bio"
+	"bufio"
 	"cmd/internal/obj"
 	"cmd/internal/sys"
 	"flag"
@@ -46,7 +46,7 @@ var (
 )
 
 func Ldmain() {
-	Bso = bio.BufWriter(os.Stdout)
+	Bso = bufio.NewWriter(os.Stdout)
 
 	Ctxt = linknew(SysArch)
 	Ctxt.Diag = Diag